Spot heating by moving a beam with horizontal rotary motion

ABSTRACT

Embodiments of the present disclosure generally relate to apparatus and methods for semiconductor processing, more particularly, to a thermal process chamber. In one or more embodiments, a process chamber comprises a first window, a second window, a substrate support disposed between the first window and the second window, and a motorized rotatable radiant spot heating source disposed over the first window and configured to provide radiant energy through the first window.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 16/923,949, filed Jul. 8, 2020, which is hereinincorporated by reference.

BACKGROUND Field

Embodiments of the present disclosure generally relate to apparatus andmethods for semiconductor processing, more particularly, to a thermalprocess chamber and spot heaters used therein.

Description of the Related Art

Semiconductor substrates are processed for a wide variety ofapplications, including the fabrication of integrated devices andmicrodevices. During processing, the substrate is positioned on asubstrate support within a process chamber. The substrate support issupported by a support shaft, which is rotatable about a central axis.Precise control over a heating source allows the substrate to be heatedwithin very strict tolerances. The temperature of the substrate canaffect the uniformity of the material deposited on the substrate.

Despite the precise control of heating the substrate, it has beenobserved that valleys (lower deposition) are formed at certain locationson the substrate. Therefore, there is a need for apparatus for improvingheating uniformity.

SUMMARY

Embodiments of the present disclosure generally relate to apparatus andmethods for semiconductor processing, more particularly, to a spotheating source, a thermal process chamber including the same, and amethod of using the same. In one or more embodiments, a process chambercomprises a first window, a second window, a substrate support disposedbetween the first window and the second window, and a motorizedrotatable radiant spot heating source disposed over the first window andconfigured to provide radiant energy through the first window.

In one or more embodiments, a spot heating source assembly comprises acollimator holder and a rotary stage disposed in a first plane, whereinthe collimator holder is mounted to the rotary stage at an acute anglewith respect to the first plane.

In one of more embodiments, a method for spot heating comprisesdisposing a substrate on a substrate support in a process chamber,activating a spot heating source mounted on a rotary stage to projectradiant energy to the substrate, moving the spot heating source along anarcuate path to adjust the impact point of the projected radiant energyon the substrate, and heating a desired area of the substrate with theprojected radiant energy.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlyexemplary embodiments and are therefore not to be considered limiting ofits scope, and may admit to other equally effective embodiments.

FIG. 1A is a schematic cross sectional side view of a process chamberaccording to one or more embodiments.

FIG. 1B is a schematic cross sectional side view of a process chamberaccording to another embodiment.

FIG. 2A is a schematic perspective side view of a spot heating sourceassembly radiation path according to one or more embodiments.

FIG. 2B is a schematic top-down view of the spot heating source assemblyof FIG. 2A according to one or more embodiments.

FIG. 2C is a schematic top-down view of a reflector according to one ormore embodiments.

FIG. 3A is a schematic cross-sectional view of the spot heating sourceassembly of FIG. 2A according to one or more embodiments.

FIG. 3B is a schematic cross-sectional view of the spot heating sourceassembly of FIG. 2A according to one or more embodiments.

FIG. 3C is a schematic cross-sectional view of the spot heating assemblyof FIG. 2A according to one or more embodiments.

FIG. 4 is a flow diagram of a method according to one or moreembodiments.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements and features of oneembodiment may be beneficially incorporated in other embodiments withoutfurther recitation.

DETAILED DESCRIPTION

Embodiments of the present disclosure generally relate to apparatus andmethods for semiconductor processing, more particularly, to a thermalprocess chamber and spot heat heating assemblies used therewith. Thethermal process chamber includes a substrate support, a first pluralityof heating elements disposed over the substrate support, and one or morespot heating source assemblies disposed over the first plurality ofheating elements. The one or more spot heating source assemblies areutilized to provide local heating to regions of lower temperature on asubstrate disposed on the substrate support during processing. Localizedheating of the substrate improves temperature profile, which in turnimproves deposition uniformity.

A “substrate” or “substrate surface,” as described herein, generallyrefers to any substrate surface upon which processing is performed. Forexample, a substrate surface may include silicon, silicon oxide, dopedsilicon, silicon germanium, germanium, gallium arsenide, glass,sapphire, and any other materials, such as metals, metal nitrides, metalalloys, and other conductive or semi-conductive materials, depending onthe application. A substrate or substrate surface may also includedielectric materials such as silicon dioxide, silicon nitride,organosilicates, and carbon dopes silicon oxide or nitride materials.The substrate itself is not limited to any particular size or shape.Although the embodiments described herein are generally made withreference to a round 200 mm, 300 mm, or 450 mm substrate, other shapes,such as polygonal, squared, rectangular, curved, or otherwisenon-circular workpieces may be utilized according to the embodimentsdescribed herein.

FIG. 1A is a schematic cross sectional side view of a process chamber100 a according to one embodiment. The process chamber 100 a is aprocess chamber for performing a thermal process, such as an epitaxialdeposition process. The process chamber 100 a includes a chamber lid103, a chamber body 148, a cover 134, and arrays of radiant heatinglamps 104 a, 104 b for heating, and, a susceptor 106 disposed within theprocess chamber 100 a. The arrays of radiant heating lamps 104 a, 104 bare disposed below and above the susceptor 106, although one of theupper array of radiant heating lamps 104 a or lower array of radiantheating lamps 104 b may be omitted. The arrays of radiant heating lamps104 a, 104 b provide a total lamp power of between about 10 KW and about60 KW. The arrays of radiant heating lamps 104 a, 104 b heat thesubstrate 102 to a temperature of between about 500 degrees Celsius andabout 900 degrees Celsius; however, other temperature ranges arecontemplated.

The arrays of radiant heating lamps 104 a, 104 b are independentlycontrolled in zones in order to control the temperature of variousregions of the substrate 102 as the process gas passes thereover, thusfacilitating the deposition of a material onto the upper surface of thesubstrate 102. While not discussed here in detail, the depositedmaterial may include silicon, doped silicon, germanium, doped germanium,silicon germanium, doped silicon germanium, gallium arsenide, galliumnitride, or aluminum gallium nitride, among other materials.

The arrays of radiant heating lamps 104 a, 104 b include a radiant heatsource, depicted here as a lamp bulb 141. Each lamp bulb 141 is coupledto a power distribution board 152, such as a printed circuit board(PCB), through which power is supplied to each lamp bulb 141. The arraysof radiant heating lamps 104 a, 104 b located beneath the second window110 are positioned within a lamphead 145, which may be cooled during orafter processing by, for example, a cooling fluid introduced intochannels 149 located between the arrays of radiant heating lamps 104 a,104 b.

The susceptor 106 is a disk-like substrate support as shown, but mayalternatively include a ring-like substrate support, which supports thesubstrate 102 from the edge of the substrate 102, exposing a backside ofthe substrate 102 to heat from the radiant heating lamps 104. Thesusceptor 106 is formed from silicon carbide or graphite coated withsilicon carbide to absorb radiant energy from the radiant heating lamps104 and conduct the radiant energy to the substrate 102, to facilitateheating the substrate 102.

The susceptor 106 is located within the process chamber 100 a between afirst window 108, and a second window 110. Each of the first window 108and the second window 110 are shaped as domes. However, it iscontemplated that the first window 108 and the second window 110 mayhave other shapes, including planar. A base ring 112 is disposed betweenthe first window 108 and second window 110. Each of the first window 108and the second window 110 is optically transparent to radiant energyprovided by the arrays of radiant heating lamps 104 a, 104 b. The firstwindow 108 is disposed between the chamber lid 103 and the susceptor106. The upper array of radiant heating lamps 104 a is disposed abovethe first window 108. A reflector 154 facilitates directing of thermalenergy from the upper array of radiant heating lamps 104 a. Similarly,the lower array of radiant heat lamps is disposed below the secondwindow 110.

The susceptor 106 includes a shaft or stem 118 that is coupled to amotion assembly 120. The motion assembly 120 includes one or moreactuators and/or adjustment devices that provide movement and/oradjustment and/or rotation of the stem 118 and/or the susceptor 106. Thesusceptor 106 may rotate at between about 5 RPM and about 100 RPM, forexample, between about 10 RPM and about 50 RPM. The susceptor 106, whilelocated in the processing position, divides the process chamber 100 ainto a process gas region 136 that is above the susceptor 106, and apurge gas region 138 below the susceptor 106. A process gas inlet 114, apurge gas inlet 164, and a gas outlet 116 are provided in the base ring112 to facilitate exposure of the substrate 102 to process gas duringprocessing. A process gas source 151 provides a process gas to theprocess gas inlet 114, and a purge gas source 162 provides a purge gasto the purge gas inlet 164. The process and purge gases flow through thegas outlet 116 to an exhaust assembly 157.

A circular shield 146 is disposed around the susceptor 106 and coupledto the base ring 112 and/or a liner 163 to prevents or minimizes leakageof heat from the radiant heating lamps 104. Additionally, a heat shield175 is disposed above the reflector 154 to block unwanted transmissionof heat. The heat shield 175 is fabricated from a metal material, forexample aluminum, and coated with gold. Substrate temperature may beindirectly measured by sensors configured to measure temperatures at thebottom of the susceptor 106. The sensors may be pyrometers disposed inports formed in the lamphead 145. Additionally, one or more temperaturesensors 153, such as a pyrometer, are directed to measure thetemperature of the device side of the substrate 102. The one or moretemperature sensors 153 are disposed through the chamber lid 103, andconfigured to detect the substrate 102 through an opening formed throughthe heat shield 175.

The process chamber 100 a further includes one or more spot heatingsource assemblies 170 (two are shown). Each spot heating source assembly170 is, for example, a laser system assembly. Power density of the lasersystem assembly may range from about 1 W/cm² to about 1000 W/cm², forexample about 1 W/cm² to about 200 W/cm², for example about 200 W/cm² toabout 1000 W/cm². Each spot heating source assembly 170 is coupled toand disposed on an upper surface of the chamber lid 103. Each spotheating source assembly 170 directs radiant energy 132 through anopening 130 (which may have an optically transparent window therein) ofthe reflector 154, through the first window 108, and toward thesusceptor 106. Radiant energy 132 from each spot heating source assembly170 is directed towards the susceptor 106 in order to impinge upon oneor more predetermined locations of the substrate 102 positioned on thesusceptor 106. The radiant energy 132 from the spot heating sourceassembly 170 selectively heats predetermined locations of the substrate,resulting in more uniform substrate temperature (and thus more uniformdeposition) during processing. The thermal energy provided by each spotheating source assembly 170 is directed to a location on the substrate102 in response to temperature measurements by the temperature sensor153 and one or more instructions from a controller 150.

Although two spot heating source assemblies 170 are shown in the processchamber 100 a, it is contemplated that one or more spot heating sourceassemblies 170 may be mounted on the process chamber 100 a, for exampletwo spot heating source assemblies 170, for example three spot heatingsource assemblies 170, for example four spot heating source assemblies170. Multiple spot heating source assemblies 170 may be mounted due tothe advantageous decreased bulk of the mounting system of each spotheating source assembly 170, particularly compared to track-mounted spotheating source assemblies.

The above-described process chamber 100 a is controlled by a processorbased system controller, such as controller 150. For example, thecontroller 150 is configured to control pressure, temperatures, and flowrates within the process chamber 100 a. By way of further example, thecontroller 150 is configured to operate the spot heating source assembly170 to facilitate improved temperature uniformity of a substrate 102.The controller 150 includes a programmable central processing unit (CPU)156 that is operable with a memory 155, support circuits 158, and a massstorage device, an input control unit, and a display unit (not shown),such as power supplies, clocks, cache, input/output (I/O) circuits, andthe like, coupled to the various components of the process chamber 100 ato facilitate control of the substrate processing. The controller 150also includes hardware for monitoring substrate processing throughsensors in the process chamber 100 a, including sensors monitoring theprecursor, process gas and purge gas flow. Other sensors that measuresystem parameters such as substrate temperature, chamber atmospherepressure and the like, may also provide information to the controller150.

FIG. 1B illustrates a cross sectional view of a process chamber 100 baccording to one or more embodiments. The process chamber 100 b issimilar to the process chamber 100 a shown in FIG. 1A, but utilizes adifferent lid 103B. The lid 103B is coupled to a clamp ring 160. Aplurality of radiant heat lamps 104 b are mounted to the lid 103Bproximate the reflector 154. One or more temperature sensors 153 arecoupled to the lid 103B and positioned to facilitate temperaturemeasurement of the substrate 102. One or more spot heating sourceassemblies 170 (one is shown) are also disposed on an upper surface ofthe chamber lid 103B and positioned to direct radiant energy to thesubstrate 102.

FIG. 2A illustrates a perspective view of the spot heating sourceassembly 170. The spot heating source assembly 170 includes a radiantspot heating source 201, a rotary stage 202, a rotary plate 205, and acooling plate 203. The radiant spot heating source 201 is disposed onand above the rotary plate 205, which in turn is disposed on and abovethe rotary stage 202, which in turn is disposed on and above the coolingplate 203. The rotary stage 202 is disposed in a first plane 284. Therotary plate 205 is disposed parallel to the first plane 284 and isrotatable within or on the rotary stage 202 to rotate the radiant spotheating source 201. Bearings, such as ball bearings and/or sealedbearings configured to withstand vacuum (e.g., vacuum-tight) or elevatedpressures without leaking, may be positioned between the rotary stage202 and the rotary plate 205 to facilitate movement therebetween. In oneor more embodiments, the radiant spot heating source 201 is mounted atan acute angle 285 with respect to the first plane 284. The acute angle285 may be within a range of about 75 degrees to about 85 degrees.However, other ranges are also contemplated, for example about 60degrees to about 90 degrees. The radiant spot heating source 201transmits energy 220 through the rotary plate 205, the rotary stage 202,and the cooling plate 203 at the acute angle 285. Openings formedthrough the rotary plate 205, the rotary stage 202, and the coolingplate 203, which accommodate radiant energy, may have sidewalls formedat an angle which matches the acute angle 285. The radiant spot heatingsource 201 is motorized (e.g., driven by a motor or other mechanicalactuator), rotatable, and configured to provide radiant energy throughthe first window 108.

The acute angle 285 at which the radiant spot heating source 201 ismounted allows the radiant spot heating source 201 to provide energy 220to the substrate 102 at an acute angle with respect to a plane of the102, which is generally perpendicular to the first plane 284. Rotatingthe rotary plate 205 to rotate the radiant spot heating source 201enables the energy 220 provided by the radiant spot heating source 201to heat the substrate 102 in a circular or semi-circular (e.g.,arc-shaped or arcuate) pattern 230 on the substrate 102. While acomplete circular pattern 230 is shown in FIG. 2A, a semicircularpattern is contemplated.

FIG. 2B illustrates a semicircular pattern 230 formed on the substrate102. In one example, the pattern 230 may be between 60 and 180 degreesof arc, such as between about 60 and 120 degrees of arc. In FIG. 2B, a180 degree path is shown solid line. However, it is contemplated that upto 360 degrees of rotation or possible, if desired. In one embodiment,one or more rotation stops are disposed on the rotary stage 202,allowing the rotary plate 205 to rotate a set amount on the rotary stage202 as defined by the one or more rotation stops. The one or morerotation stops restrict the rotation of the rotary plate 205 to createthe desired pattern 230. In one example, the stops may be two posts thatextend vertically from an upper surface of the rotary stage 202. Anextension, which extends in a cantilevered manner from the rotary plate205, is positioned between the posts and travels therebetween as therotary plate 205 rotates. The extension of the rotary plate 205 contactsthe posts as the rotary plate rotates, thereby limiting the rotation ofthe rotary plate. It is contemplated that the posts may be positioned atpredetermined positions to allow a predetermined degree of rotation ofthe rotary plate

The radiant spot heating source 201 is configured to heat any point fromthe center to the outer edge of the substrate 102. The pattern 230 mayextend for example from the center of the substrate 102 to the outercircumference of the substrate 102. Due to the angled mounting of theradiant spot heating source 201, the position of the location of theenergy 220 with respect to distance from the center of the substrate 102may be determined by a pre-programmed algorithm. In some examples, theposition of the radiant spot heating source 201 remains fixed duringprocessing. In other examples, the spot heating source is moved duringprocessing while applying radiant energy. In such an example, theimpingement location of the radiant energy may be swept back and forthacross substrate surface as the substrate is rotated.

The rotary stage 202 is disposed on a cooling plate 203, which isdisposed on the chamber lid 103. In one or more embodiments, the coolingplate 203 comprises aluminum. In one or more embodiments, the rotarystage 202 is disposed in direct contact with the cooling plate 203, tofacilitate thermal transfer therebetween. The rotary stage 202 and thecooling plate 203 may be formed from materials with relatively highthermal conductivity, such as metals, for example, aluminum or aluminumalloys. The cooling plate 203 comprises channels 240 that flow a coolingfluid, for example water, through the cooling plate 203 in order tofacilitate temperature control of the spot heating source assembly 170.In one or more embodiments, the channels 240 comprise one or morealuminum, stainless steel, and/or copper pipes.

The rotary stage 202 is configured to rotate about a vertical axis 207.In one or more embodiments, the rotary stage 202 is coupled to anactuator, such as a motor, configured to rotate the rotary plate 205about the rotary stage 202. The motor may be any suitable motor, forexample an optical grade motor optimized for accuracy, such as steppermotor. The rotary stage 202 may include a plurality of bearings tofacilitate rotation of the rotary plate 205 about the vertical axis 207.

In one or more embodiments, the radiant spot heating source 201 includesa collimator holder 204. The collimator holder 204 is mounted to therotary stage 202 at an acute angle with respect to the first plane 284.The radiant spot heating source 201 also includes a collimator 206disposed within the collimator holder 204, operable to provide radiantspot heating to a region of the susceptor 106 and/or the substrate 102positioned thereon. The collimator holder 204 facilitates support of thecollimator 206. The collimator holder 204 may house one or more lensestherein. While the collimator 206 may receive optical energy from, orfacilitate support of, an optical energy source such as a laser. Asillustrated in FIG. 2A, an optical energy source 299, such as a laser,is engaged with collimator 206. In one example, each of the collimatorholder 204 and the collimator 206 include housing formed from aluminum.

Power applied to the radiant spot heating source may vary depending onthe use case. For example, power can be less than 100 W, for examplefrom about 10 W to about 90 W, for example from about 20 W to about 80W, for example from about 40 W to about 60 W. Power may vary during asingle application depending on the location of the spot being heatedwith respect to the center of the substrate 102. In one or moreembodiments, power may remain fixed during an application or process.Wavelength of the radiant source output may be any suitable value, forexample between 900 nm to 1000 nm, for example about 970 nm.

FIG. 2C is a schematic top-down view of the reflector 154 according toone or more embodiments. As discussed above, the reflector 154 includesone or more openings 130 through which the radiant energy 132 isdirected to the susceptor 106. The openings 130 have a curved shape toaccommodate the rotation of the spot heating source assemblies 170 asthe spot heating source assemblies 170 are rotated. Additionally, theheat shield 175 (shown in phantom) is disposed above the reflector 154.The heat shield 175 additionally includes openings 295 formed therein.The openings 295 depicted herein are a curved oblong shape such that theradiant energy 132 (shown in FIG. 1A) from the spot heating sourceassemblies 170 may travel in the semicircular pattern 230, shown in FIG.2B. The openings 130 and 295 are angularly offset (though may overlap)relative to one another. The angular offset between the openings 130 and295 allows the radiant energy 132 to traverse the openings 130 and 295when the radiant energy 132 is directed at angular relative to verticaldue to the rotation of the spot heating source assembly 170 and verticaloffset of the openings 130 and 295.

FIG. 3A illustrates a schematic cross-sectional view of the spot heatingsource assembly 170 of FIG. 2A in which the collimator holder 204 isfree of lenses mounted therein. The spot heating source assembly 170includes a rotary stage 202, a rotary plate 205, a collimator holder204, and a collimator 206. FIG. 3B illustrates a schematiccross-sectional view of the spot heating source assembly 170 of FIG. 2Ain which the collimator holder includes one lens 300 mounted therein.FIG. 3C illustrates a schematic cross-sectional view of the spot heatingsource assembly 170 of FIG. 2A in which the collimator holder comprisesa plurality of lenses 300 mounted therein. The one or more lenses 300are formed from any suitable material, for example quartz, and may becoated in an anti-reflective coating. The one or more lenses 300disposed within the collimator holder 204 allow for varied focal lengthsthat enable heat provided by the spot heating source assembly 170 tocontact various spot sizes on the substrate 102. It is contemplated thatthe lenses 300 may include concave lenses, convex lenses, Fresnellenses, or other lens designs.

FIG. 4 schematically illustrates operations of a method 400 forprocessing a substrate. In some embodiments, the method 400 may locallyheat the substrate in an epitaxial deposition chamber.

At operation 410, a substrate is disposed on a substrate support of aprocess chamber. In some embodiments, the process chamber may be anepitaxy deposition chamber, for example the process chamber 100 a, 100 bshown in FIG. 1A. However, other process chambers are contemplated.

At operation 420, a spot heating source mounted on a rotary stage isactivated to project radiant energy to the substrate. The activation mayinclude powering a laser source, such as a diode laser source. Theactivation may heat an area, portion, or specific region of thesubstrate 102. The activation may last for any length of time and maybe, in certain embodiments a constant firing and/or a pulsed firing. Inpulsed firing, the laser source may have a duty cycle less than 50%, forexample 25%, for example 5%, for example 1%. The time between pulses inthe pulsed firing may be between about 10 microseconds (μs) to about 10milliseconds (ms), for example between about 0.5 ms to about 5 ms. Theactivation may heat a desired area, portion, or region of the substratein order to reduce a cold spot thereon to provide a more uniformtemperature across the substrate. It is further contemplated that othertypes of lasers or radiant energy sources may be utilized. In oneembodiment, the spot heating source is moved along an arcuate path toadjust the impact point of the projected radiant energy on thesubstrate.

At operation 430, a desired area of the substrate is heated followingactivation of the radiant spot heating source mounted on a rotary stage.In one or more embodiments, the substrate support is rotated whileheating the desired area of the substrate. In one or more embodiments,the rotary stage is rotated while heating the desired area of thesubstrate. In one or more embodiments, the substrate support and therotary stage are rotated while heating the desired area of thesubstrate. It is also contemplated that the rotary stage may be rotatedprior to activation of the radiant spot heater, to directed radiantenergy a predetermined location.

It is contemplated that while process chambers for epitaxial depositionare shown and described herein, the subject matter of the presentdisclosure is also applicable to other process chambers that are capableof providing a controlled thermal cycle that heats the substrate forprocesses such as, for example, thermal annealing, thermal cleaning,thermal chemical vapor deposition, thermal oxidation and thermalnitridation, regardless of whether the heating elements are provided atthe top, bottom, or both the top and bottom of the process chamber.

Benefits of the present disclosure include a reduction in temperaturenon-uniformities on a substrate, creating a substrate with a moreuniform material deposition thereon. A cost reduction is also realizedin that there is an increase in substrate quality, and thus, a reductionin scrap. Additional benefits include precise local heating of thesubstrate for ultra-fine tuning of temperature uniformity. Furtherbenefits of the present disclosure include decreased bulk compared toconventional approaches. The decreased bulk improves overall lifetime ofthe assembly, as there is less wear on components of the system.Additionally, the disclosed spot heaters mitigate sealing issues presentwith linear and vertical slotted mounting mechanisms, thus facilitatingmaintenance of a high pressure environment. The maintained pressurefurther facilitates cooling of the lamp module, thereby extending thelongevity and effectiveness of the process chamber and componentsthereof.

In summation, embodiments described herein provide an epitaxialdeposition chamber that includes a spot heating source assembly forproviding heating of a substrate during processing. Energy may befocused to locally heat and tune specific locations of the substrate.The spot heating source assembly comprises a collimator holder disposedon a rotary stage, operable to heat portions of a substrate withoutallowing light and air to escape the substrate processing region. Thisassembly prevents hazards related to unwanted light and air flow out ofthe substrate processing region, and provides a long-lasting assemblywith minimized bulk and cost.

While the foregoing is directed to embodiments of the presentdisclosure, other and further embodiments of the disclosure may bedevised without departing from the basic scope thereof, and the scopethereof is determined by the claims that follow.

What is claimed is:
 1. A process chamber, comprising: a first window; asecond window; a substrate support disposed between the first window andthe second window; a rotary stage disposed in a first plane above thefirst window; and a motorized rotatable radiant spot heating sourcedisposed over the first window and configured to provide radiant energythrough the first window, such that the motorized rotatable radiant spotheating source is mounted to the rotary stage and positioned at an acuteangle with respect to the first plane, wherein the rotary stage isrotatable to rotate the motorized rotatable radiant spot heating sourceabout a rotational axis orthogonal to the first plane.
 2. The processchamber of claim 1, wherein the rotational axis passes through therotary stage.
 3. The process chamber of claim 2, wherein the rotationalaxis also passes through the motorized rotatable spot heating source. 4.The process chamber of claim 3, wherein the rotational axis isnon-parallel with a longitudinal axis of the motorized rotatable radiantspot heating source.
 5. The process chamber of claim 4, wherein acooling plate is disposed in a second plane parallel to the first plane.6. The process chamber of claim 5, wherein the rotary stage is disposedin direct contact with the cooling plate.
 7. The process chamber ofclaim 3, wherein the motorized rotatable radiant spot heating source isconfigured to direct radiant energy in a ring-shaped pattern across asurface of a substrate disposed of the substrate support.
 8. The processchamber of claim 7, wherein a distance from the motorized rotatableradiant spot heating source to the ring-shaped pattern on the surface ofthe substrate is equidistant at all points along the ring shapedpattern.
 9. The process chamber of claim 2, wherein the motorizedrotatable radiant spot heating source comprises: a collimator holder;and a collimator disposed in the collimator holder.
 10. A processchamber, comprising: a first window; a substrate support disposedproximate the first window; a rotary stage disposed in a first plane;and a motorized rotatable radiant spot heating source mounted to therotary stage and configured to provide radiant energy through the firstwindow toward the substrate support, the motorized rotatable radiantspot heating source positioned at an acute angle with respect to thefirst plane, wherein the rotary stage rotatable to rotate the motorizedrotatable radiant spot heating source about a rotational axis orthogonalto the first plane.
 11. The spot heating source assembly of claim 10,wherein the rotational axis passes through the rotary stage.
 12. Thespot heating source assembly of claim 11, further comprising: acollimator disposed on a collimator holder; and a laser coupled to thecollimator.
 13. The spot heating source assembly of claim 10, whereinthe collimator holder comprises at least one lens mounted therein. 14.The spot heating source assembly of claim 13, wherein the rotationalaxis is non-parallel with a longitudinal axis of the motorized rotatableradiant spot heating source.
 15. The spot heating source assembly ofclaim 14, The process chamber of claim 3, wherein the motorizedrotatable radiant spot heating source is configured to direct radiantenergy in a ring-shaped pattern across a surface of a substrate disposedof the substrate support.
 16. The spot heating source assembly of claim15, wherein a distance from the motorized rotatable radiant spot heatingsource to the ring-shaped pattern on the surface of the substrate isequidistant at all points along the ring shaped pattern.
 17. A methodfor spot heating, comprising: disposing a substrate on a substratesupport in a process chamber; activating a spot heating source mountedon a rotary stage to project radiant energy to the substrate, the rotarystage mounted in a fixed location relative to a chamber lid of theprocess chamber; rotating the spot heating source to direct theprojected radiant energy along an arcuate path on the substrate, whereina travel distance of the projected radiant energy between the spotheating source and the arcuate path on the substrate is substantiallyequal at each point along the arcuate; and heating a desired area of thesubstrate with the projected radiant energy.
 18. The method of claim 17,further comprising: rotating the substrate support while heating thedesired area of the substrate.
 19. The method of claim 17, furthercomprising: rotating the rotary stage while heating the desired area ofthe substrate.
 20. The method of claim 17, further comprising: rotatingthe substrate support and the rotary stage while heating the desiredarea of the substrate.